How to use sandbox Push Notifications?

Hi,


I am working in an app with push notifications. We have the certificate for development and production. I get the notifications on the device when deploying the code from XCode. But I need to send a test version to TestFlight as well, so others testers can test it. But we want to test a build with the sandox, not the productions servers. How do I set up to have my build installed from TestFlight to use the development push notifications certificate/servers?


Best Regards,

Milene